To study vascular lesions induced by viruses and the possible role of such injury as an initiating or contributing factor in the development of atherosclerosis. The mouse will be employed as the experimental host. Special attention will be given to group B coxsackieviruses since there is some evidence that these agents may be implicated in certain cases of this disease in man. The mouse model was selected since these viruses have been shown to induce cardiovascular injury and disease in the mouse, resembling that in man. Mice will be infected with group B coxsackieviruses: i before and ii after blood cholesterol level have been elevated by an hyperlipemic diet. The cardiovascular tissues from these mice will be studied for direct injury, during the acute infection, as well as indirect injury (or transformation) resulting from persisting viral antigen. Fluorescent microscopy, electron microscopy and biochemical techniques will be employed. The sequelae of the resulting cardiovascular lesions will be followed histopathologically, and the result correlated with biochemical viral and serologic tests. The influence of genetic factors and the natural history of these processes will also be examined. These data will then be examined for similarities to the atherosclerosis process in man.